package com.itheima.controller;

import com.itheima.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.util.UUID;

@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {
    @Value("${reggie.path}")
    private String basePath;
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file)  {
        //file是一个临时文件，需要转存到指定位置，否则请求完成后临时文件会删除
        log.info(file.toString());
        
        //原始文件名
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID随机生成文件名，防止因为文件名相同造成文件名覆盖
        String fileName = UUID.randomUUID().toString()+suffix;

        //创建一个目录对象
        File dir=new File(basePath);
        if(!dir.exists()){
            dir.mkdirs();
        }

        try {
            file.transferTo(new File(basePath+fileName));
        } catch (IOException e) {
           e.printStackTrace();
        }
        return R.success(fileName);//返回文件名
    }
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) {

        FileInputStream fileInputStream = null;
        try {
            //通过输入流读取文件内容
            fileInputStream = new FileInputStream(new File(basePath + name));
            //通过输出流将文件写回浏览器，在浏览器显示图片
            ServletOutputStream outputStream = response.getOutputStream();
            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len=fileInputStream.read(bytes)) != -1) {
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }


    }
}
